Josh Marshall has a fascinating post about why Obama has done so poorly in West Virginia, Tennessee, Pennsylvania, and the surrounding areas:

There’s been a lot of talk in this campaign about Barack Obama’s problem with working class white voters or rural voters. But these claims are both inaccurate because they are incomplete. You can look at states like Virginia, Ohio, Pennsylvania and other states and see the different numbers and they are all explained by one basic fact. Obama’s problem isn’t with white working class voters or rural voters. It’s Appalachia.

The post also has a convincing map of all the counties where Clinton has won over 65% of the vote.